A rolling stone gathers no moss. (Here the participle rolling functions as an adjective and modifies the noun stone.)

Just then an unexpected visitor turned up.

Participial relative clause

A participial relative clause is a clause which resembles a relative clause but which contains a participle instead of a finite verb. In the following examples, the first member of the pair contains a participial relative clause while the second contains an equivalent full relative clause.

The passengers injured in the accident were taken to hospital.

The passengers who were injured in the accident were taken to hospital.